Investigation of trapped rubidium atoms through frequency-modulation-induced coherent transient effects

We investigated coherent transient oscillations in the transmission intensi ty of a frequency-modulated probe-laser beam through a sample of trapped at oms. The transients occur when the frequency of the probe-laser beam crosse s a resonance of the atoms in a time of the order of the lifetime of the ex cited state. A theoretical description used previously to explain transient effects observed in Mossbauer spectroscopy has been developed further to a dapt for the specific frequency- and amplitude-modulation characteristics o f current-modulated laser diodes. The transients were recorded at various e xperimental parameters, and the results of the experiments were compared wi th results obtained from slow frequency sweeps and independent measurements of the modulation characteristics of the laser. The results show that the theory accurately explains the coherent transient phenomena. (C) 1998 Optic al Society of America. [S0740-3224(98)01912-2]. OCIS codes: 020.1670, 020.7 010.